British Post Offices. Callao. 1878 (July 12), envelope from Lima to London, with 1876 10c tied by dispatch cds, GB 1874-80 6d pair pl. 15, tied by "C38" oval, London transit on front, carried via Panama by the "Para", Callao cds on reverse, fine and scarce. (Image)

Callao. 1875 (Feb 6) envelope to Birmingham bearing single and pair of 1873-80 6d pl. 13, cancelled by "C38" barred ovals, with matching dispatch cds at left and arrival on reverse, minor cover edge imperfections; cert. B.P.A. (2006). (Image)

Callao. 1877 (May 12) registered envelope from Callao to Derby, England, bearing Peru 1876 10c (2) in combination with GB 1865 4d pl. 14 (defective), 1873 1s pl. 12 and 1867 2s pl. 1, all cancelled by "C38" of Callao with cds alongside, together with two strikes of red "REGISTERED" straight line and London oval ds, bs on receipt, cover edge imperfections, a rare registered mail; cert. Holcombe (1989). (Image)

Callao. 1877 (Sept 7) entire letter datelined at Arequipa posted at Callao and sent to London, franked by GB 1874 6d pl. 15 marginal pair and 1867 2s marginal single (corner torn before application), tied by "C43" barred ovals, Callao and London bs; cert. Holcombe (1989). (Image)